Patent Document 1 describes an exhaust heat recovery device in which a valve configured to control a flow of exhaust is used to recover exhaust heat in a heat recovery chamber when heat recovery is necessary (for example, when the heat is used for heating in a winter season or the like) and to directly discharge the exhaust by causing the exhaust to flow to a bypass route when the heat recovery is unnecessary.
In the aforementioned exhaust heat recovery device, a heat recovery material is arranged inside a tubular exhaust pipe and an annular heat medium flow passage is arranged outside the exhaust pipe. Heat of high-temperature exhaust (for example, exhaust of an engine of an automobile) flowing inside the exhaust pipe is recovered via the heat recovery material by heat medium such as water flowing through the heat medium flow passage.
Moreover, in the aforementioned exhaust heat recovery device, the heat medium is supplied to the heat medium flow passage from a heat medium supply pipe extending on one side of the annular heat medium flow passage, and the heat medium in the heat medium flow passage is collected by a heat medium collection pipe extending on the other side of the annular heat medium flow passage.